The Relationship between Diurnal Measures of Tonic Alertness and Self-Reported Fatigue in Persons with Multiple Sclerosis-A Retrospective Data Analysis.

These results show a relationship between subjective fatigue and tonic alertness. However, other variables also contribute to this association, suggesting that the RT differences between twice-daily measures of tonic alertness is not related to increased subjective fatigue in a substantial number of pwMS, which diminishes the diagnostic value. Further studies including relevant variables such as sleepiness are urgently needed.